Vermiculite Insulation and Asbestos -
Information for Manitobans

Vermiculite

Vermiculite is a mineral used in a number of consumer products,
including home insulation. Some vermiculite produced at Libby Mine
in Montana from the 1920s until 1990, sold primarily under the brand
name Zonolite®, has been found to contain asbestos. While not all
vermiculite produced before 1990 contains asbestos fibres, it is
reasonable to assume that if a building has older vermiculite-based
insulation, it may contain some asbestos.

Asbestos

Asbestos is the generic name for fibrous minerals found naturally in
rock formations around the world. Because asbestos fibres are
strong, durable and non-combustible, they were widely used by
industry, mainly in construction and friction materials.

When inhaled in significant quantities, and over extended periods of
time, exposure to asbestos can cause asbestosis (a scarring of the
lungs which makes breathing difficult), mesothelioma (a rare cancer
of the lining of the chest or abdominal cavity) and other types of
lung cancer. Approximately 80 per cent of cases of mesothelioma are
as a result of exposure to asbestos. Therefore, numbers of
mesothelioma cases are often used as a marker for asbestos exposure
in a population.

Cases of mesothelioma are rare, typically ranging between 5 and 20
cases per year in Manitoba (an approximate rate of one case per
100,000 Manitobans per year). This number of cases has gradually
increased since the early 1970s, when surveillance for mesothelioma
in Manitoba began. As there is a 30 to 40 year latency period
(delay) between exposure to asbestos and the occurrence of
mesothelioma, this increase in cases is believed to be due to
exposures that occurred before the implementation of safety measures
which reduced the risk for contact to asbestos in workplace
environments. Improvements in disease surveillance systems have also
increased the ability to accurately identify and report cases. With
the introduction of measures to improve workplace safety, it is
anticipated that the trend in mesothelioma and other
asbestos-related diseases will begin to decline over the next one to
two decades.

Vermiculite insulation

Of the 45,455 homes evaluated for energy efficiency across Canada as
part of Natural Resource Canada's EnerGuide for Houses Program from
June 1, 2004 to March 22, 2005, vermiculite insulation was observed
in 1,674 (or 3.7 per cent) of houses. 3,184 of the homes evaluated
were in Manitoba and 215 (6.6 per cent) of these homes contained
vermiculite insulation.

In 2004, Indian and Northern Affairs Canada (INAC) conducted a
national survey of First Nations homes. Of the 597 references to
Zonolite® identified, 234 were in Manitoba.

Horticultural Vermiculite

Health Canada recently concluded national testing of horticultural
(gardening) vermiculite products. This testing revealed mostly
non-detected amounts of asbestos, with a few samples showing trace
amounts of tremolite asbestos fibres. Based on these low levels,
Health Canada has determined that the use of horticultural
vermiculite, when used as directed by consumers, poses no additional
risk of cancer. The United States’ Environmental Protection Agency
has conducted similar testing and come to the same conclusion – that
horticultural vermiculite is considered safe and does not pose an
elevated risk of cancer to the user.

Minimizing your risk

According to the Health Canada advisory “Vermiculite Insulation
Containing Amphibole Asbestos”, the best way to minimize your risk
of asbestos exposure is to avoid disturbing vermiculite-based
insulation. If vermiculite-based insulation is contained and not
exposed to the home or interior environment, it poses very little
risk.

If you know you have, or believe you may have, vermiculite-based
insulation in your attic, the following precautionary steps are
recommended:

Seal all cracks and holes in the ceilings of the rooms below the
insulation (for example, apply caulking around light fixtures and
the attic hatch) to prevent insulation sifting through.

Restrict access to the attic. Do not allow children to play in an
attic with open areas of vermiculite-based insulation.

Make sure anyone working in the attic knows about the possible
presence of asbestos.

Do not use the attic for storage if retrieving items from it may
disturb the insulation.

If you must go into the attic, walk on boards in order to minimize
disturbance of the insulation and use an appropriate respirator
mask. Common dust masks are not effective protection against
asbestos fibres. Half-face N, P, or R-100 respirators can be used
and are available from retailers who sell safety equipment.

Do not remain in the attic any longer than is necessary.

If you suspect that you have vermiculite-based insulation in your
walls, as a precautionary step, seal all cracks and holes. For
example, apply caulking around window and door frames, along
baseboards and around electrical outlets.

If you decide to have vermiculite-based insulation removed, or if
you are planning renovations, speak to a professional qualified in
dealing with asbestos. They can be found by looking under "asbestos
abatement/removal” in the yellow pages. You should not attempt to
remove the insulation yourself, unless you have been properly
trained and have the necessary specialized equipment.

What to do if you are concerned that you may have been exposed to
asbestos

Asbestos related illnesses are usually associated with frequent and
prolonged exposure to asbestos. The time it takes to develop disease
following exposure to asbestos is usually measured in decades.
However, there are some steps you can take if you have concerns
about exposure to asbestos:

Talk to your health care provider. Currently, there are no
effective screening methods to determine if exposure to asbestos has
occurred. For those with more frequent/prolonged exposure, your
health care provider may recommend having a chest X-ray and/or refer
you to a specialist.

Avoid or minimize further exposure to any form of asbestos. This
includes making sure future work is done safely, as well as proper
clean up of the area.

Don’t smoke, and avoid second hand tobacco smoke and other
irritants that could affect your lungs. The combination of exposure
to cigarette smoke and asbestos greatly increases the chance of
developing lung cancer.

For information on this issue, Health Canada provides a toll-free
contact number: 1-800-443-0395. You can also visit the Health Canada
website to view the It’s Your Health advisory.
Information can also be provided through your local public health
office.

For workers and employers with questions related to a workplace,
please contact the Workplace Safety and Health Division of Manitoba
Labour at 204-945-3446.